US10568523B2 - Heat monitoring instrument and thermal therapy apparatus - Google Patents

Abstract

A heat monitoring instrument of the invention includes: an insertion portion for inserting into tissue of a subject; a distal end portion that constitutes a distal end portion of the insertion portion and receives and transmits heat of the subject into which the insertion portion is inserted; and a shape-memory portion that constitutes the distal end portion and changes shape due to the heat of the subject.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of PCT/JP2014/084300 filed on Dec. 25, 2014 and claims benefit of Japanese Application No. 2014-050571 filed in Japan on Mar. 13, 2014, the entire contents of which are incorporated herein by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat monitoring instrument that monitors the state of an increase in the temperature of tissue of a subject when executing thermal therapy, and a thermal therapy apparatus.

2. Description of the Related Art

Thermal therapy is known that is performed with respect to tissue of an organism such as a human where the subject's tissue is heated. Thermal therapy, for example, causes tissue to generate heat by applying a high-frequency voltage, microwaves radio waves or by irradiation of ultrasound with respect to tissue from a thermal therapy instrument inserted into the body of the subject. As disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 8-308853, thermal therapy is used for therapy that kills tumor cells in tissue and the like.

In the case of heating tissue by thermal therapy, heat is conveyed to the therapy object and to tissue surrounding the therapy object, where it is desirable to avoid a situation in which the heating affects tissue that is not the therapy object. Consequently, a technique is proposed that monitors the temperature of tissue using thermography or a thermocouple when executing thermal therapy.

SUMMARY OF THE INVENTION

A heat monitoring instrument according to one aspect of the present invention includes: an insertion portion for inserting into tissue of a subject; a distal end portion that constitutes a distal end portion of the insertion portion, the distal end portion receiving and transmitting heat of the subject into which the insertion portion is inserted; and a shape-memory portion that constitutes the distal end portion and changes shape due to the heat of the subject.

A thermal therapy apparatus according to one aspect of the present invention includes: the heat monitoring instrument, a thermal therapy instrument that heats the tissue, and a drive apparatus that actuates the thermal therapy instrument; wherein the drive apparatus stops operation of the thermal therapy instrument in a case where a change in shape of the heat monitoring instrument is detected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a configuration of a heat monitoring instrument according to a first embodiment;

FIG. 2 is a view illustrating a state in which a locking portion changes shape in the heat monitoring instrument of the first embodiment;

FIG. 3 is a schematic diagram illustrating a state in which the heat monitoring instrument of the first embodiment is inserted into tissue;

FIG. 4 is a view illustrating the manner of performing thermal therapy using the heat monitoring instrument of the first embodiment;

FIG. 5 is a view illustrating an example of thermal therapy;

FIG. 6 is a view illustrating another example of thermal therapy;

FIG. 7 is a view illustrating a first modification of an insertion portion and the locking portion of the first embodiment;

FIG. 8 is a view illustrating a second modification of the insertion portion and the locking portion of the first embodiment;

FIG. 9 is a view illustrating a third modification of the insertion portion and the locking portion of the first embodiment;

FIG. 10 is a view illustrating a fourth modification of the insertion portion and the locking portion;

FIG. 11 is a view illustrating a configuration of a heat monitoring instrument according to a second embodiment;

FIG. 12 is a schematic diagram illustrating a state in which the heat monitoring instrument of the second embodiment is inserted into tissue;

FIG. 13 is a view illustrating a state in which a T-shaped locking portion is housed inside a cylindrical member;

FIG. 14 is a view illustrating a state in which a coil-shaped locking portion is housed inside a cylindrical member;

FIG. 15 is a view illustrating the heat monitoring instrument of the second embodiment that includes a pressing member;

FIG. 16 is a view illustrating the heat monitoring instrument of the second embodiment in which a thermal therapy instrument is configured as a pressing member;

FIG. 17 is a view illustrating a first modification of the cylindrical member of the second embodiment;

FIG. 18 is a view illustrating a second modification of the cylindrical member of the second embodiment;

FIG. 19 is a view illustrating a third modification of the cylindrical member of the second embodiment;

FIG. 20 is a view illustrating a heat monitoring instrument of a third embodiment;

FIG. 21 is a schematic diagram illustrating a state in which the heat monitoring instrument of the third embodiment is inserted into tissue;

FIG. 22 is a view illustrating a heat monitoring instrument and a pulling apparatus of a fourth embodiment;

FIG. 23 is a cross-sectional diagram illustrating the configuration of the pulling apparatus of the fourth embodiment;

FIG. 24 is a view illustrating a state in which a proximal end portion of a linear member is held by the pulling apparatus of the fourth embodiment;

FIG. 25 is a view illustrating a state in which, in the fourth embodiment, the insertion portion of the linear member is withdrawn from tissue or a cylindrical member;

FIG. 26 is a view illustrating a heat monitoring instrument and a pulling apparatus of a fifth embodiment;

FIG. 27 is a cross-sectional diagram illustrating the configuration of the pulling apparatus of the fifth embodiment;

FIG. 28 is a view illustrating a state in which a proximal end portion of the linear member is held by the pulling apparatus of the fifth embodiment;

FIG. 29 is a view illustrating the configuration of a heat monitoring instrument according to a sixth embodiment;

FIG. 30 is a view illustrating a state in which a switch portion changes shape in the heat monitoring instrument of the sixth embodiment;

FIG. 31 is a view illustrating the configuration of a heat monitoring instrument according to a seventh embodiment;

FIG. 32 is a view illustrating a state in which a switch portion changes shape in the heat monitoring instrument of the seventh embodiment;

FIG. 33 is a view illustrating the configuration of a heat monitoring instrument according to an eighth embodiment; and

FIG. 34 is a view illustrating a state in which a switch portion changes shape in the heat monitoring instrument of the eighth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are described hereunder with reference to the accompanying drawings. Note that the respective components in the respective drawings used for the following description are displayed in a contraction scale which differs according to each component so as to be shown in a size that is recognizable in the drawings, and the present invention is not limited only to the quantity of components, the shapes of components, the ratios between the sizes of components, and the relative positional relationships between the respective components illustrated in the drawings.

First Embodiment

Aheat monitoring instrument1 of the present embodiment that is shown inFIG. 1 is an apparatus that, when performing thermal therapy that heats predetermined tissue with respect to an organism such as a human as a subject, allows a user to perceive the state of a change in temperature in peripheral tissue accompanying the thermal therapy.

Theheat monitoring instrument1 includes aninsertion portion2, alocking portion3 that is provided in theinsertion portion2, and alinear member4 that is coupled to theinsertion portion2.

Thelinear member4 is an elongated member having a linear shape that is made of metal, resin, fiber or the like. The shape and material of thelinear member4 is not particularly limited as long as thelinear member4 is a member that withstands a tensile force (a tensile force that is applied in a longitudinal direction) of a predetermined size. For example, thelinear member4 may be of a form that, like string, easily buckles and changes shape in a case where a compressive force is applied in the longitudinal direction. Further, for example, thelinear member4 may be of a form that, like a piece of wire, even in a case where a compressive force is applied in the longitudinal direction, does not buckle until the compressive force exceeds a predetermined value. That is, as long as thelinear member4 is a member that transmits a tensile force in a longitudinal direction, thelinear member4 may be of a form that transmits a compressive force, or may be of a form that does not transmit a compressive force in the longitudinal direction.

Note that, although the thickness in the longitudinal direction of thelinear member4 of the present embodiment that is shown in the drawings is fixed, thelinear member4 may also have a shape in which the cross-sectional shape in the longitudinal direction changes. Further, thelinear member4 need not be constituted by only a single member, and may be constituted by a plurality of members. For example, thelinear member4 may have a form in which a plurality of members are present within the same cross-section, like twine, or may have a form in which a plurality of members are connected in the longitudinal direction, like a chain.

Adistal end portion4athat is one end part of thelinear member4 is coupled to theinsertion portion2. Note that, thelinear member4 and theinsertion portion2 may also be formed integrally by a single member.

Theinsertion portion2 is a part that is inserted into tissue of an organism such as a human as the subject, or into a conduit that is provided in an endoscope or a cylindrical member that can be introduced into the body of an organism, such as a needle tube that can be pierced into the tissue of an organism.

The lockingportion3 is provided in theinsertion portion2. As described later, the external shape of theinsertion portion2 differs between a case where the temperature thereof is less than or equal to a predetermined temperature and a case where the temperature thereof is in a predetermined temperature range that exceeds the predetermined temperature. Note that, it is sufficient that theinsertion portion2 has a structure that changes shape in a case where theinsertion portion2 is heated from a state of the predetermined temperature or less to a temperature in the predetermined temperature range, and theinsertion portion2 need not change shape in a case where the temperature thereof falls from the state in the predetermined temperature range to the predetermined temperature or less. That is, a change in shape caused by a change in the temperature of theinsertion portion2 may be irreversible.

In a case where theinsertion portion2 is inserted into the tissue of an organism and the temperature of theinsertion portion2 is less than or equal to the predetermined temperature, the lockingportion3 engages with the surrounding tissue. In this case, if a force in a direction to withdraw theinsertion portion2 from inside the tissue is applied to theinsertion portion2, the lockingportion3 generates a resistance force that retains theinsertion portion2 inside the tissue against the aforementioned force. Further, in a case where theinsertion portion2 is inserted to a predetermined position inside the cylindrical member and the temperature of the lockingportion3 is less than or equal to the predetermined temperature, the lockingportion3 engages with an engagement portion that is provided in the cylindrical member. If a force in a direction to withdraw theinsertion portion2 from inside the tissue is applied to theinsertion portion2, the lockingportion3 generates a resistance force that retains theinsertion portion2 inside the cylindrical member against the aforementioned force.

That is, in a case where theinsertion portion2 is inserted inside tissue or into the cylindrical member and the temperature of theinsertion portion2 is less than or equal to a predetermined temperature, even if a tensile force is applied to thelinear member4 by pulling the proximal end side of thelinear member4, because the lockingportion3 is engaged with the tissue or the cylindrical member, theinsertion portion2 stays inside the tissue or inside the cylindrical member. Note that, if an excessive tensile force of an extent such that the lockingportion3, the tissue or the cylindrical member deforms greatly or breaks is applied to thelinear member4, naturally theinsertion portion2 will drop out.

Further, in a case where theinsertion portion2 is inserted into tissue of an organism and theinsertion portion2 is heated from a state of the predetermined temperature or less to the predetermined temperature range, theinsertion portion2 changes shape and the locking function of the lockingportion3 disappears, and the engagement between the lockingportion3 and the tissue or the cylindrical member is released.

That is, in a case where theinsertion portion2 is inserted into tissue or into the cylindrical member, and theinsertion portion2 is heated to the predetermined temperature range, if a tensile force is applied to thelinear member4 by pulling the proximal end side of thelinear member4, theinsertion portion2 will come out from inside the tissue or inside the cylindrical member.

Next, a specific configuration of theinsertion portion2 and the lockingportion3 will be described. As one example according to the present embodiment, theinsertion portion2 has a form that is to be inserted into tissue of an organism such as a human that is the subject.FIG. 1 illustrates a case where the temperature of the lockingportion3 is less than or equal to a predetermined temperature.

As shown inFIG. 1, theinsertion portion2 of the present embodiment is composed of a member having a linear shape. The lockingportion3 is provided at adistal end portion2athat is one end portion of theinsertion portion2. Aproximal end portion2bthat is the other end portion of theinsertion portion2 is coupled to thedistal end portion4aof thelinear member4. Theinsertion portion2 according to the present embodiment is made of a shape-memory alloy that changes shape when heated to a predetermined temperature range that exceeds a predetermined temperature.

When the temperature of theinsertion portion2 is less than or equal to the predetermined temperature, the lockingportion3 has a shape such that thedistal end portion2aof theinsertion portion2 that is made of a shape-memory alloy that has a linear shape bends backwards.

Specifically, as indicated by reference symbol θ inFIG. 1, the lockingportion3 has a shape in which theinsertion portion2 bends at an angle of 90 or more at a position that is a predetermined length from the distal end of theinsertion portion2. That is, the lockingportion3 has a hook-like shape in a case where the temperature of theinsertion portion2 is less than or equal to a predetermined temperature. This kind of shape of the lockingportion3 is referred to as a “barb” or the like with respect to a fish hook or an arrowhead.

Hence, in a case where theinsertion portion2 is inserted inside the tissue of an organism such as a human as a subject, and the temperature of theinsertion portion2 is less than or equal to a predetermined temperature, the lockingportion3 that has a hook shape engages with the surrounding tissue.

Note that, although in the present embodiment that is illustrated in the drawings a bent portion of the lockingportion3 is substantially a V-shape, the bent portion may be substantially a U-shape that is rounded.

In a case where theinsertion portion2 is heated from a state in which theinsertion portion2 is a predetermined temperature to a predetermined temperature range that exceeds the predetermined temperature, as shown inFIG. 2, theinsertion portion2 changes shape so as to eliminate the bend in theinsertion portion2. That is, in a state in which theinsertion portion2 is heated to the predetermined temperature range and changes shape, the lockingportion3 runs along the longitudinal direction of theinsertion portion2, and the lockingportion3 and theinsertion portion2 become a rectilinear shape.

Hence, in a case where theinsertion portion2 is inserted into the tissue of an organism such as a human as the subject, and theinsertion portion2 is heated from a state in which theinsertion portion2 is the predetermined temperature or less to a temperature in the predetermined temperature range, the lockingportion3 that is a hook shape changes shape into a rectilinear shape to thereby release the engagement with the tissue.

A value of the predetermined temperature in this case is not particularly limited, and is arbitrarily set according to the conditions under which theheat monitoring instrument1 is used. As one example in the present embodiment, the predetermined temperature is set from 42° C. to 45° C. A predetermined temperature from 42° C. to 45° C. is a temperature at which tumor cells are killed, but at which healthy cells survive. Note that the predetermined temperature may also be less than 42° C. or may exceed 45° C.

Next, the action of theheat monitoring instrument1 of the present embodiment will be described.FIG. 3 is a schematic diagram illustrating the manner in which thermal therapy is performed on tissue of an organism that includes tumor cells.FIG. 3 illustrates a cross-section ofcertain tissue10 of an organism such as a human, and atarget site11 that is composed of tumor cells or the like as a therapy object exists at the cross-section in question. Note that, the object of thermal therapy may be a malignant tumor such as pancreatic cancer, hepatic cancer, renal cancer, lung cancer, prostatic cancer or malignant lymphoma, or may be a benign tumor such as uterine myoma or endometriosis.

In the thermal therapy, thetarget site11 is heated by athermal therapy instrument20 that is inserted into thetissue10 or by thethermal therapy instrument20 that is disposed outside of thetissue10. In this case, thethermal therapy instrument20 is an apparatus that causes thetissue10 to generate heat by application of a high-frequency voltage such as microwaves or radio waves or by irradiation of ultrasound. As one example according to the present embodiment, it is assumed that tissue that is present around adistal end portion20aof thethermal therapy instrument20 is heated by an operation of thethermal therapy instrument20 that is inserted inside thetarget site11. Note that, so-called “high-intensity focused ultrasound (HIFU)” in which ultrasound is irradiated from thethermal therapy instrument20 so as to focus on thetarget site11 is known as a method for causing thetarget site11 to generate heat by means of thethermal therapy instrument20 that is disposed outside thetissue10. The specific configuration of thethermal therapy instrument20 is known, and a detailed description thereof is therefore omitted herein.

Before performing thermal therapy, theinsertion portion2 of theheat monitoring instrument1 is inserted into thetissue10, and the lockingportion3 is disposed at a location at which it is desired to detect the state of a change in temperature inside thetissue10. As one example according to the present embodiment, the location at which the lockingportion3 is disposed so as to detect the state of a change in temperature inside thetissue10 is between thedistal end portion20aof thethermal therapy instrument20 and ablood vessel12. Note that the location at which the lockingportion3 is disposed is not limited thereto, and may be a boundary portion between thetarget site11 that is the tumor cells and the healthy cells, or may be inside thetarget site11.

The insertion path of theinsertion portion2 into thetissue10 may be a path that passes through the skin from outside the body of the subject, or a path that passes from inside the digestive tract of the subject through a tubular wall of the digestive tract, or may be a path that passes from inside a body cavity through an outer wall of an internal organ having thetissue10. An operation to insert theinsertion portion2 of theheat monitoring instrument1 to a predetermined position inside thetissue10 is performed, for example, under observation by means of an ultrasound diagnostic apparatus such as an ultrasound endoscope.

In a state in which theinsertion portion2 of theheat monitoring instrument1 is inserted inside thetissue10, aproximal end portion4bof thelinear member4 is extended to outside of the internal organ that has thetissue10. Theproximal end portion4bof thelinear member4 may also be extended as far as outside the body of the subject in a state in which theinsertion portion2 is inserted inside thetissue10.

In a state in which theinsertion portion2 of theheat monitoring instrument1 is inserted inside thetissue10 and the lockingportion3 is disposed inside the tissue10 (state shown inFIG. 3), because the temperature of theinsertion portion2 is lower than the predetermined temperature that is 42° C. to 45° C., the lockingportion3 engages with the surroundingtissue10. Consequently, even in a case where a tensile force T is applied to theproximal end portion4bside of thelinear member4, and a force is applied to theinsertion portion2 in a direction to withdraw theinsertion portion2 from inside thetissue10, the position of theinsertion portion2 inside thetissue10 does not change.

That is, in a case where the temperature of thetissue10 in which the lockingportion3 is disposed is less than or equal to the predetermined temperature, even if thelinear member4 that extends to outside thetissue10 is pulled by a finger of the user or by an apparatus of some kind, theheat monitoring instrument1 will remain inserted inside thetissue10. In other words, in a case where theinsertion portion2 of theheat monitoring instrument1 does not drop out from inside thetissue10 even when the tensile force T is applied to thelinear member4, the user can determine that the temperature of thetissue10 at the location at which theinsertion portion2 is disposed is less than or equal to the predetermined temperature.

When thethermal therapy instrument20 is actuated to start thermal therapy, thetissue10 around thedistal end portion20aof thethermal therapy instrument20 generates heat. Because heat that is generated by operation of thethermal therapy instrument20 is transmitted to the surroundingtissue10, a region in which the temperature of thetissue10 exceeds the predetermined temperature (42° C. to 45° C.) spreads to the surrounding area as time passes from the start of thermal therapy. InFIG. 4, a region in which the temperature of thetissue10 exceeds the predetermined temperature is indicated by a dashed line.

Further, as shown inFIG. 4, when the region in which the temperature of thetissue10 exceeds the predetermined temperature extends as far as the location at which theinsertion portion2 is disposed, the lockingportion3 changes shape and the engagement between the lockingportion3 and thetissue10 is released. Consequently, in a case where a tensile force T is applied to theproximal end portion4bside of thelinear member4 and a force is applied to theinsertion portion2 in a direction to withdraw theinsertion portion2 from inside thetissue10, theinsertion portion2 drops out from thetissue10.

That is, in a case where the temperature of thetissue10 at which theinsertion portion2 is disposed is heated up to the predetermined temperature range that exceeds the predetermined temperature, if thelinear member4 that extends to outside of thetissue10 is pulled by a finger of the user or by some kind of apparatus, theheat monitoring instrument1 will be withdrawn from thetissue10. In other words, in a case where the tensile force T is applied to thelinear member4 and as a result theinsertion portion2 of theheat monitoring instrument1 drops out from inside thetissue10, the user can determine that thetissue10 at the location at which theinsertion portion2 is disposed has been heated up to the predetermined temperature range.

An example of performing thermal therapy with respect to apancreas13 that has thetissue10 in which thetarget site11 that is composed of tumor cells is present will now be described referring toFIG. 5. In the example illustrated inFIG. 5, in a state in which the human that is the subject reclines on the left side, anultrasound endoscope30 is inserted into thestomach14 that is part of the digestive tract, and thermal therapy is performed on thepancreas13 from inside thestomach14 using thethermal therapy instrument20 that is protruded from adistal end portion31aof theultrasound endoscope30.

The configuration of theultrasound endoscope30 as well as the thermal therapy that is performed using theultrasound endoscope30 and thethermal therapy instrument20 are known, and hence a detailed description is omitted here.

Theultrasound endoscope30 has aninsertion portion31 that can be introduced into inside the subject, and anoperation portion32 that is located at a proximal end of theinsertion portion31. Anultrasound transducer31bfor sending and receiving ultrasound, an image pickup apparatus for picking up optical images, an illumination apparatus, and a distal-end-side opening portion31cof atreatment instrument channel34 and the like are provided at thedistal end portion31aof theinsertion portion31.

An ultrasound image obtained by driving theultrasound transducer31band an optical image obtained by driving the image pickup apparatus are displayed on an unshown image display apparatus that is connected through auniversal cord33 that extends from theoperation portion32.

Thetreatment instrument channel34 is a conduit that is inserted through the inside of theinsertion portion31. A proximal-end-side opening portion34bof thetreatment instrument channel34 opens at theoperation portion32. By inserting thethermal therapy instrument20 into thetreatment instrument channel34 from the proximal-end-side opening portion34b, thedistal end portion20aof thethermal therapy instrument20 can be protruded from the distal-end-side opening portion34a.

According to the thermal therapy shown inFIG. 5, theinsertion portion31 of theultrasound endoscope30 is inserted into thestomach14, and under observation by means of an optical image and an ultrasound image using theultrasound endoscope30, theinsertion portion2 of theheat monitoring instrument1 is inserted from inside thestomach14 into thetissue10 of thepancreas13. As described above, according to the present embodiment theinsertion portion2 is disposed between thetarget site11 and theblood vessel12. In this case, theliner member4 extends to outside the body of the subject via a conduit provided in theultrasound endoscope30.

The conduit through which thelinear member4 is inserted until thelinear member4 exits to outside the body of the subject may be thetreatment instrument channel34 through which thethermal therapy instrument20 is inserted, or may be a conduit that is provided in theultrasound endoscope30 separately from thetreatment instrument channel34. Further, the conduit through which thelinear member4 is inserted may be a cylindrical member that is inserted inside the subject separately from theultrasound endoscope30.

A tensile force T can be applied to thelinear member4 that is extended to outside the body of the subject, by, for example, the user using a finger to grasp theproximal end portion4b. Further, for example, a tensile force T can be applied to thelinear member4 by a method that fixes a weight having a predetermined weight to theproximal end portion4b, or by a method that connects a pulling apparatus that uses a spring, an electric motor or the like to theproximal end portion4b.

Further, thethermal therapy instrument20 is protruded from the distal-end-side opening portion34athat is provided in thedistal end portion31aof theinsertion portion31. Thethermal therapy instrument20 is inserted into thetissue10 of thepancreas13 from inside thestomach14, and thermal therapy that heats thetumor cells11 is started.

Subsequently, upon the temperature of theinsertion portion2 being heated up to the predetermined temperature range that exceeds the predetermined temperature as a result of heat of the thermal therapy being transmitted to the surrounding area, theinsertion portion2 changes shape and the engagement between the lockingportion3 and thetissue10 is released, and consequently theinsertion portion2 drops out from thetissue10. Withdrawal of theinsertion portion2 from thetissue10 can be confirmed, for example, by observation by means of an optical image and an ultrasound image using theultrasound endoscope30. In a case where thelinear member4 is pulled by a finger of the user, the user can directly perceive withdrawal of theinsertion portion2 from thetissue10 as a result of the tensile force that was being applied to thelinear member4 fading. By confirming the withdrawal of theinsertion portion2 from thetissue10, the user can determine that thetissue10 at the location at which theinsertion portion2 had been disposed is heated to the predetermined temperature range.

In this connection, although according to the example illustrated inFIG. 5 theproximal end portion4bof thelinear member4 extends to outside the body of the subject in a state in which theinsertion portion2 of theheat monitoring instrument1 is inserted inside thetissue10 of thepancreas13, as illustrated as one example inFIG. 6, a form may also be adopted in which theproximal end portion4bof thelinear member4 extends to inside the body of the subject (into the stomach14).

In the example illustrated inFIG. 6, theinsertion portion31 of theultrasound endoscope30 is inserted into thestomach14, and under observation by means of an optical image and an ultrasound image using theultrasound endoscope30, theinsertion portion2 of theheat monitoring instrument1 is inserted into thetissue10 of thepancreas13 from inside thestomach14. As described above, in the present embodiment theinsertion portion2 is disposed between thetumor cells11 and theblood vessel12. In this case, theproximal end portion4bof thelinear member4 extends as far as the inside of thestomach14.

A weight7 is fixed to thelinear member4 that extends as far as the inside of thestomach14. A tensile force T is applied to thelinear member4 as a result of the weight7 being fixed to thelinear member4. That is, the weight7 is a pulling apparatus that produces a force in a direction to withdraw theinsertion portion2 of theheat monitoring instrument1 from thetissue10. Note that, the weight7 may also be integrated with theproximal end portion4bof thelinear member4.

Thethermal therapy instrument20 is then protruded from the distal-end-side opening portion34athat is provided in thedistal end portion31aof theinsertion portion31, thethermal therapy instrument20 is inserted into thetissue10 of thepancreas13 from inside thestomach14, and the thermal therapy for heating thetarget site11 is started.

Subsequently, upon the temperature of the lockingportion3 being heated to the predetermined temperature range that exceeds the predetermined temperature as a result of the heat of the thermal therapy being transmitted to the surrounding area, the lockingportion3 changes shape and the engagement between the lockingportion3 and thetissue10 is released, and consequently theinsertion portion2 drops out from thetissue10. Withdrawal of theinsertion portion2 from thetissue10 can be confirmed, for example, by observation by means of an optical image and an ultrasound image using theultrasound endoscope30. By confirming withdrawal of theinsertion portion2 from thetissue10, the user can determine that thetissue10 at the location at which theinsertion portion2 is disposed is heated up to the predetermined temperature range.

As described above, according to the present embodiment, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy. Further, because theheat monitoring instrument1 of the present embodiment has a simple structure in which the lockingportion3 is provided in theinsertion portion2 that is made of a shape-memory alloy, and thelinear member4 is coupled to theinsertion portion2, theheat monitoring instrument1 can be manufactured at a low cost.

For example, in a case where the lockingportion3 is disposed between thetarget site11 and theblood vessel12 as in the present embodiment and thermal therapy is performed while applying the tensile force T to thelinear member4, if the thermal therapy is stopped when theinsertion portion2 comes out from thetissue10, it is possible to prevent theblood vessel12 from being heated to a temperature that exceeds the predetermined temperature. As described above, because the predetermined temperature is a temperature at which tumor cells are killed and healthy cells survive, the heating by the thermal therapy does not affect theblood vessel12. Thus, by using theheat monitoring instrument1 in thermal therapy that kills tumor cells, heating by the thermal therapy can be prevented from affecting normal tissue around thetarget site11 that is composed of the tumor cells.

Note that, in addition to the above described use, theheat monitoring instrument1 of the present embodiment can also be used to allow a user to perceive whether or not tissue is heated to a temperature that exceeds the predetermined temperature by thermal therapy in order to determine whether or not thermal therapy has been sufficiently performed. Hence, when using theheat monitoring instrument1, a location at which the lockingportion3 is disposed inside thetissue10 is not limited to the above described embodiment, and may be appropriately decided according to the use.

For example, if the lockingportion3 is disposed in the vicinity of the outside of thetarget site11, if theinsertion portion2 drops out the user can determine that theentire target site11 is heated to a temperature at which tumor cells are killed.

Further, for example, if thetissue10 in which thetarget site11 is present is a site that is sensitive to heating, such as the pancreas, in some cases it is desired to prevent healthy tissue on the outside of thetarget site11 from being heated so as to suppress side effects that are caused by thermal therapy. In this case, if the lockingportion3 is disposed at a position in the vicinity of the outer circumference of thetarget site11 that is a position that is inside thetarget site11, an increase in the temperature of thetissue10 outside thetarget site11 can be prevented.

Theheat monitoring instrument1 that is described above is an apparatus that perceives a temperature change in tissue of a subject by means of a change in shape of theinsertion portion2 that is made of a shape-memory alloy. Although in the present embodiment theheat monitoring instrument1 is used in a case of heating the tissue of a subject, theheat monitoring instrument1 can also be used for cryotherapy that freezes the tissue of a subject. In this case, theinsertion portion2 of theheat monitoring instrument1 is configured so as to change shape so that engagement between the lockingportion3 and the tissue is released if the temperature falls below a predetermined temperature, for example, 0° C.

Next, a modification of theinsertion portion2 and the lockingportion3 will be described. Although the above-describedlocking portion3 is a hook-like shape, the lockingportion3 is not limited thereto. The lockingportion3 may be a portion having a shape that, in a case where theinsertion portion2 is inserted into thetissue10 of an organism and the temperature of theinsertion portion2 is less than or equal to the predetermined temperature, produces a force that retains theinsertion portion2 inside thetissue10 against a force in a direction to withdraw theinsertion portion2, and changes shape so that such a resistance force fades when the temperature of theinsertion portion2 is heated to a predetermined temperature range that exceeds the predetermined temperature.

FIG. 7 is a view illustrating a first modification of theinsertion portion2 and the lockingportion3. As shown inFIG. 7, in a case where the temperature of the lockingportion3 of the present embodiment is less than or equal to the predetermined temperature, thedistal end portion2aof theinsertion portion2 that is made of a linear shape-memory alloy has a shape which is wound in a coil shape. In a case where the lockingportion3 is heated to the predetermined temperature range that exceeds the predetermined temperature, as shown by a chain double-dashed line inFIG. 7, the lockingportion3 changes shape to become a rectilinear shape.

FIG. 8 is a view that illustrates a second modification of theinsertion portion2 and the lockingportion3. As shown inFIG. 8, in a case where the temperature of the lockingportion3 of the present embodiment is less than or equal or to the predetermined temperature, thedistal end portion2aof theinsertion portion2 that is made of a linear shape-memory alloy has a shape which is bent in substantially a T-shape. Specifically, the lockingportion3 has a shape which turns back at an angle of approximately 180 degrees at a point A that is a distance of a predetermined length L1 on the proximal end side from the distal end of theinsertion portion2, and is further bent at an angle of approximately 90 degrees at a point B that is a distance of a length L2 which is shorter than the length L1 on the proximal end side from the point A. In a case where the lockingportion3 is heated to the predetermined temperature range that exceeds the predetermined temperature, as shown by a chain double-dashed line inFIG. 8, the lockingportion3 changes shape into a rectilinear shape.

FIG. 9 is a view that illustrates a third modification of theinsertion portion2 and the lockingportion3. As shown inFIG. 9, thedistal end portion2aof theinsertion portion2 of the present embodiment is divided into a plurality of portions, and the lockingportion3 is provided on each of thedistal end portions2a.

FIG. 10 is a view that illustrates a fourth modification of theinsertion portion2 and the lockingportion3. In the present embodiment, theinsertion portion2 is a member having a linear shape. The lockingportion3 is a member that is fixed to thedistal end portion2aof theinsertion portion2, and has an outer shape that protrudes to the sides of thedistal end portion2awhen the temperature is less than or equal to the predetermined temperature.

The lockingportion3 of the present embodiment is constituted by a material that melts or softens in a case where the material is heated to a predetermined temperature range that exceeds a predetermined temperature. The material constituting the lockingportion3 is, for example, beeswax, bone wax or paraffin. In the present embodiment, in a case where the lockingportion3 is heated to the predetermined temperature range that exceeds the predetermined temperature and a force in a withdrawing direction is applied to theinsertion portion2, the lockingportion3 changes shape in accordance with the force, and consequently the engagement between the lockingportion3 and thetissue10 is released.

Even in the case of the modifications illustrated inFIG. 7 toFIG. 10, as described above, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy. Further, because theheat monitoring instrument1 according to these modifications has a simple structure in which the lockingportion3 is fixed to the distal end portion of a member having a linear shape, theheat monitoring instrument1 can be manufactured at a low cost.

Second Embodiment

A second embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the first embodiment are described, and components that are the same as in the first embodiment are denoted by the same reference numerals and a description of such components is omitted as appropriate.

As shown inFIG. 11, theheat monitoring instrument1 of the present embodiment differs from the first embodiment in that theheat monitoring instrument1 of the present embodiment includes acylindrical member5.

Thecylindrical member5 is a hollow tubular member, and it is possible to insert theinsertion portion2, the lockingportion3 and thelinear member4 through the inside thereof. As one example according to the present embodiment, thecylindrical member5 is a needle tube having a shape that is diagonally cut in the longitudinal direction to make it easy for thedistal end portion5ato pierce thetissue10 of the organism. Theproximal end portion4bof thelinear member4 extends to the outside from the proximal end portion of thecylindrical member5. Note that thedistal end portion5aof thecylindrical member5 may also be a shape that is cut at a face that is perpendicular to the longitudinal direction.

In the present embodiment, the form of theinsertion portion2 and the lockingportion3 is not limited to a form in which the lockingportion3 is a hook shape as shown in the drawing, and may be a form of a modification described referring toFIG. 7 toFIG. 10 in the first embodiment.

When using theheat monitoring instrument1 of the present embodiment, thecylindrical member5 is pierced into thetissue10 in a state in which theinsertion portion2 and lockingportion3 are contained inside thecylindrical member5, and thereafter, as shown inFIG. 12, theinsertion portion2 and the lockingportion3 are disposed inside thetissue10 by moving thecylindrical member5 to the proximal end side relative to theinsertion portion2, the lockingportion3 and thelinear member4. Note that, thecylindrical member5 may be of a form that moves relatively by the amount of only a predetermined distance towards the proximal end side from the distal end portion3aof the lockingportion3, or may be of a form that moves relatively as far as theproximal end portion4bof thelinear member4 so that theinsertion portion2, the lockingportion3 and thelinear member4 come out from the inside of thecylindrical member5.

Thus, according to the present embodiment, because theinsertion portion2 and the lockingportion3 are inserted into thetissue10 using thecylindrical member5, an operation to dispose theinsertion portion2 and the lockingportion3 at a predetermined location of thetissue10 is facilitated.

For example, in a case where the shape of the lockingportion3 is the coil shape shown inFIG. 7 or the T-shape shown inFIG. 8, because there is a large amount of resistance when theinsertion portion2 is inserted into thetissue10 in a state in which the lockingportion3 is exposed, insertion of theinsertion portion2 as far as a deep position is difficult. According to the present embodiment, as shown inFIG. 13 andFIG. 14, by housing the lockingportion3 that is a T-shape or a coil shape inside thecylindrical member5, it is possible to easily insert theinsertion portion2 and the lockingportion3 as far as a predetermined location in thetissue10.

In the embodiment shown inFIG. 13 and inFIG. 14, in a state in which the lockingportion3 is contained inside thecylindrical member5, the lockingportion3 elastically changes shape to a shape that fits within the inner diameter of thecylindrical member5. The lockingportion3 expands based on the elasticity thereof when the lockingportion3 is brought outside of thecylindrical member5 inside thetissue10, and returns to a shape that engages with thetissue6 as shown inFIG. 7 andFIG. 8.

In the present embodiment also, similarly to the first embodiment, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy. Further, because theheat monitoring instrument1 has a simple structure, theheat monitoring instrument1 can be manufactured at a low cost.

Note that, as long as thelinear member4 is of a form that does not easily buckle with respect to a compressive force in the longitudinal direction, as in the case of, for example, a metal wire, an operation to move thecylindrical member5 to the proximal end side relative to theinsertion portion2, the lockingportion3 and thelinear member4 inside thetissue10 can be easily performed by merely pulling thecylindrical member5 in the proximal end direction while keeping thelinear member4 fixed.

However, in a case where thelinear member4 has a flexible form such as string, an operation is required to push out theinsertion portion2 and the lockingportion3 relatively from inside thecylindrical member5 to the distal end side. Therefore, in a case where thelinear member4 has a flexible form such as string, as shown inFIG. 15, a pressingmember6 is arranged inside thecylindrical member5. Thepressing member6 is a member that is longer than thecylindrical member5, and has an outer diameter that is smaller than the inner diameter of thecylindrical member5. Thepressing member6 has stiffness such that thepressing member6 does not buckle even if a force of an amount required for pushing out theinsertion portion2 and the lockingportion3 from inside thecylindrical member5 into thetissue10 is applied in the axial direction. Note that, as shown inFIG. 16, thethermal therapy instrument20 that is inserted through the inside of thecylindrical member5 may also be used as the pressingmember6.

Although in the present embodiment that is described above thecylindrical member5 has the form of a needle tube, the form of thecylindrical member5 is not limited thereto.

For example, as shown as a first modification inFIG. 17, thecylindrical member5 may also be of a form that includes a plurality of conduits. According to the present modification that is illustrated inFIG. 17, thecylindrical member5 includes twoconduits5band5c. Theheat monitoring instrument1 is inserted through one of the conduits, i.e. theconduit5b, and thethermal therapy instrument20 is inserted through the other conduit, i.e. theconduit5c.

As shown as a second modification inFIG. 18, in a case where thecylindrical member5 has a plurality of conduits, the opening portions on the distal end side of the respective conduits may be provided apart from each other in the longitudinal direction of thecylindrical member5. In the present modification illustrated inFIG. 18, thecylindrical member5 has aconduit5bthrough which theheat monitoring instrument1 is inserted, and aconduit5cthrough which thethermal therapy instrument20 is inserted. Theconduit5copens at the distal end of thecylindrical member5, and theconduit5bopens at a position on the proximal end side that is separated from the distal end of thecylindrical member5 by a predetermined distance.

Further, for example, as shown as a third modification inFIG. 19, thecylindrical member5 may be of a form that includes twoconduits5band5c, in which theheat monitoring instrument1 is inserted through theconduit5b, and theinsertion portion31 of theultrasound endoscope30 is inserted through theconduit5c. A cylindrical member through which theultrasound endoscope30 is inserted in this manner is referred to as an “overtube” or the like.

Even in the case of the modifications illustrated inFIG. 17 toFIG. 19, as described above, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy. Further, because theheat monitoring instrument1 according to these modifications has a simple structure, theheat monitoring instrument1 can be manufactured at a low cost.

Third Embodiment

A third embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the first and second embodiments are described, and components that are the same as in the first and second embodiments are denoted by the same reference numerals and a description of such components is omitted as appropriate.

In the foregoing first and second embodiments, in a case where theinsertion portion2 of theheat monitoring instrument1 is inserted inside thetissue10 and the temperature is less than or equal to the predetermined temperature, the lockingportion3 engages with the surroundingtissue10. In contrast, according to the present embodiment, in a case where theinsertion portion2 of theheat monitoring instrument1 is inserted inside thecylindrical member5 and the temperature is less than or equal to the predetermined temperature, the lockingportion3 engages with thecylindrical member5.

As shown inFIG. 20, theheat monitoring instrument1 includes thecylindrical member5, and theinsertion portion2 andlinear member4 that are inserted through the inside of thecylindrical member5. The lockingportion3 is provided at thedistal end portion2aof theinsertion portion2.

As one example according to the present embodiment, thecylindrical member5 is a needle tube that can be pierced into thetissue10. A through-hole5dis formed in the wall face in the vicinity of thedistal end portion5aof thecylindrical member5.

Similarly to the first and second embodiments, thelinear member4 is an elongated member having a linear shape that is made of metal, synthetic resin or the like.

Theinsertion portion2 is composed of a member having a linear shape. The lockingportion3 is provided at thedistal end portion2athat is one end portion of theinsertion portion2. Theproximal end portion2bthat is the other end portion of theinsertion portion2 is coupled to thedistal end portion4aof thelinear member4. Theinsertion portion2 of the present embodiment is made of a shape-memory alloy that changes shape into a rectilinear shape when heated to a predetermined temperature range that exceeds a predetermined temperature. Note that, thelinear member4 and theinsertion portion2 may also be formed integrally by a single member.

The lockingportion3 is formed by bending thedistal end portion2aof theinsertion portion2 that is made of a linear shape-memory alloy into a hook shape in a state in which the temperature of theinsertion portion2 is less than or equal to the predetermined temperature. The lockingportion3 protrudes to the outside of thecylindrical member5 through the through-hole5dformed in the wall face of thecylindrical member5. Hence, in a case where the temperature of the lockingportion3 is less than or equal to a predetermined temperature, the lockingportion3 engages with thecylindrical member5.

Further, in a state in which the lockingportion3 is engaged in the through-hole5dof thecylindrical member5, theproximal end portion4bof thelinear member4 extends to the outside from the proximal end of thecylindrical member5.

If the lockingportion3 is heated from the state in which the temperature thereof is the predetermined temperature up to the predetermined temperature range that exceeds the predetermined temperature, as shown by a chain double-dashed line inFIG. 20, the lockingportion3 changes shape to become a rectilinear shape. Hence, in a case where the lockingportion3 is heated up to the predetermined temperature range from the state in which the temperature thereof is less than or equal to the predetermined temperature, the lockingportion3 changes shape to become a rectilinear shape to thereby release the engagement with thecylindrical member5.

When using theheat monitoring instrument1 of the present embodiment when performing thermal therapy, as shown inFIG. 21, thecylindrical member5 of theheat monitoring instrument1 is inserted into thetissue10, and the lockingportion3 is disposed at a location at which it is desired to detect the state of a change in temperature inside thetissue10. As one example according to the present embodiment, the location at which the lockingportion3 is disposed so as to detect the state of a change in temperature inside thetissue10 is between thedistal end portion20aof thethermal therapy instrument20 and ablood vessel12. Note that, the location at which the lockingportion3 is disposed is not limited thereto, and may be a boundary portion between thetarget site11 that is the tumor cells and the healthy cells, or may be inside thetarget site11.

The insertion path of thecylindrical member5 into thetissue10 may be a path that passes through the skin from outside the body of the subject, or a path that passes from inside the digestive tract of the subject through a tubular wall of the digestive tract, or a path that passes from inside a body cavity through an outer wall of an internal organ having thetissue10. An operation to insert thecylindrical member5 to a predetermined position inside thetissue10 is performed, for example, under observation by means of an ultrasound diagnostic apparatus such as theultrasound endoscope30. Similarly to the first and second embodiments, a tensile force T is applied by means of a finger of the user or by a pulling apparatus of some kind (for example, a weight7) to thelinear member4.

When thethermal therapy instrument20 is operated and the temperature of the lockingportion3 is heated to the predetermined temperature range that exceeds the predetermined temperature as a result of the heat of the thermal therapy being transmitted to the surrounding area, the lockingportion3 changes shape and the engagement between the lockingportion3 and thecylindrical member5 is released and theinsertion portion2 drops out from thecylindrical member5. By confirming the withdrawal of theinsertion portion2 from thecylindrical member5, the user can determine that thetissue10 at the location at which the lockingportion3 had been disposed is heated to the predetermined temperature range.

As described above, according to the present embodiment, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy. Further, because theheat monitoring instrument1 of the present embodiment has a simple structure, theheat monitoring instrument1 can be manufactured at a low cost.

Fourth Embodiment

A fourth embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the first to third embodiments are described, and components that are the same as in the first to third embodiments are denoted by the same reference numerals and a description of such components is omitted as appropriate.

In the present embodiment, a pullingapparatus40 that applies the tensile force T to thelinear member4 when using theheat monitoring instrument1 described in the first to third embodiments when performing thermal therapy will be described. As one example according to the present embodiment, as shown inFIG. 22, it is assumed that thermal therapy is performed on the subject using theultrasound endoscope30 and thethermal therapy instrument20.

Theproximal end portion4bof thelinear member4 of theheat monitoring instrument1 extends from the proximal-end-side opening portion34bthrough thetreatment instrument channel34 that is a conduit provided in theultrasound endoscope30. The pullingapparatus40 is fixed to the proximal-end-side opening portion34bof thetreatment instrument channel34 of theultrasound endoscope30.

As shown inFIG. 23, the pullingapparatus40 has a configuration that includes abase portion41, aslider42, a holdingportion43 and an urgingmember44.

Thebase portion41 is a member that is fixed to the proximal-end-side opening portion34b. A through-hole41ais formed in thebase portion41. In a state in which thebase portion41 is fixed to the proximal-end-side opening portion34b, anend41bof the through-hole41afaces the proximal-end-side opening portion34b. Accordingly, in a state in which thebase portion41 is fixed to the proximal-end-side opening portion34b, the through-hole41aand thetreatment instrument channel34 are connected.

Theslider42 is a member that moves relatively with respect to thebase portion41. Theslider42 moves relatively with respect to thebase portion41 along the central axis of the through-hole41a. The holdingportion43 is fixed to theslider42.

The holdingportion43 is a member that moves relatively with respect to thebase portion41 along the central axis of the through-hole41atogether with theslider42. The holdingportion43 is arranged facing anotherend41cof the through-hole41athat is provided in thebase portion41. That is, the holdingportion43 moves forward/rearward along the central axis of the through-hole41aso that a distance between the holdingportion43 and theother end41cof the through-hole41achanges.

The holdingportion43 has a structure that holds theproximal end portion4bof thelinear member4. Holding of theproximal end portion4bof thelinear member4 by the holdingportion43 can be released by an operation of the user. According to the present embodiment that is illustrated in the drawings, as one example the holdingportion43 has a configuration that pinches theproximal end portion4bof thelinear member4 from the sides like a clip.

The urgingmember44 is a member made of a spring or the like that urges theslider42 in a direction away from the proximal-end-side opening portion34b. In other words, the urgingmember44 urges the holdingportion43 in a direction away from theother end41cof the through-hole41aalong the central axis of the through-hole41a.

When performing thermal therapy, as shown inFIG. 24, in a state in which the holdingportion43 is brought near to the other end of theother end41cof the through-hole41aagainst the urging force of the urgingmember44, theproximal end portion4bof thelinear member4 that extends from the proximal-end-side opening portion34bis held by the holdingportion43. By this means, since the urging force of the urgingmember44 is transmitted to thelinear member4, the tensile force T is applied to thelinear member4.

Further, when heating is performed such that the temperature of the lockingportion3 of theheat monitoring instrument1 reaches the predetermined temperature range that exceeds the predetermined temperature, because the engagement between the lockingportion3 and thetissue10 or thecylindrical member5 is released, theinsertion portion2 is caused to withdraw from inside thetissue10 or inside thecylindrical member5 by the urging force of the urgingmember44. At such time, as shown inFIG. 25, the holdingportion43 is moved in a direction away from theother end41cof the through-hole41a. Therefore, apart from observation using an optical image and an ultrasound image using theultrasound endoscope30, the user can confirm that theinsertion portion2 has been withdrawn from thetissue10 or thecylindrical member5 by looking at the movement of the holdingportion43.

Thus, according to the present embodiment, similarly to the above described first to third embodiments, when performing thermal therapy, by using theheat monitoring instrument1 the user can easily and reliably know the state of an increase in the temperature of tissue at a desired location during performance of the thermal therapy.

Fifth Embodiment

A fifth embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the fourth embodiment are described, and components that are the same as in the fourth embodiment are denoted by the same reference numerals and a description of such components is omitted as appropriate.

As shown inFIG. 27, the pullingapparatus40 of the present embodiment includes awithdrawal detection portion45 that detects that theinsertion portion2 is withdrawn from thetissue10 or thecylindrical member5. Thewithdrawal detection portion45 detects the fading of the tensile force T that the pullingapparatus40 applies to thelinear member4. In a case where the tensile force T fades, thewithdrawal detection portion45 determines that theinsertion portion2 has been withdrawn from thetissue10 or thecylindrical member5.

Thethermal therapy instrument20 is connected to adrive apparatus21 that drives thethermal therapy instrument20. Thethermal therapy instrument20 and thedrive apparatus21 constitute a thermal therapy apparatus. Thewithdrawal detection portion45 is electrically connected to thedrive apparatus21 of thethermal therapy instrument20 through anelectric cable46.

Thedrive apparatus21 actuates thethermal therapy instrument20 during only a period in which, for example, afootswitch22 is placed in an “on” state by the user. Further, if withdrawal of theinsertion portion2 from thetissue10 or thecylindrical member5 is detected by thewithdrawal detection portion45 during operation of thethermal therapy instrument20, thedrive apparatus21 stops operation of thethermal therapy instrument20.

Although the configuration of thewithdrawal detection portion45 is not particularly limited, as shown inFIG. 27, as one example according to the present embodiment, thewithdrawal detection portion45 takes the form of a push switch that is switched on or off in accordance with forward/rearward movement of theslider42 and the holdingportion43.

Thewithdrawal detection portion45 that is a push switch is fixed to thebase portion41. As shown inFIG. 28, in a state in which theslider42 and the holdingportion43 are adjacent to theother end41cof the through-hole41a, thewithdrawal detection portion45 comes into contacts with theslider42 and enters an “on” state. That is, in a state in which the holdingportion43 is brought close to the other end of theother end41cof the through-hole41aagainst the urging force of the urgingmember44, thewithdrawal detection portion45 enters an “on” state in a state in which theproximal end portion4bof thelinear member4 is held by the holdingportion43 and the tensile force T is applied to thelinear member4.

On the other hand, in a state in which the tensile force T is not being applied to thelinear member4, that is, in a state in which theslider42 and the holdingportion43 are positioned at a location that is separated from theother end41cof the through-hole41aby the urging force of the urgingmember44, thewithdrawal detection portion45 separates from theslider42 and enters an “off” state.

When thewithdrawal detection portion45 enters an “off” state during operation of thethermal therapy instrument20, thedrive apparatus21 stops operation of thethermal therapy instrument20.

The thermal therapy apparatus of the present embodiment configured as described above automatically stops thethermal therapy instrument20 in a case where theinsertion portion2 withdraws from thetissue10 or thecylindrical member5 during performance of the thermal therapy. Therefore, in a case where the lockingportion3 of theheat monitoring instrument1 is heated such that the temperature thereof enters the predetermined temperature range that exceeds the predetermined temperature, thethermal therapy instrument20 can be reliably stopped.

Sixth Embodiment

A sixth embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the first to fifth embodiments are described, and components that are the same as in the first to fifth embodiments are denoted by the same reference numerals and a description of such components is omitted as appropriate.

In the foregoing embodiments, confirmation of a change in the shape of theinsertion portion2 of theheat monitoring instrument1 is performed based on a change in a tensile force that is applied to thelinear member4. In contrast, according to the present embodiment, confirmation of a change in the shape of theinsertion portion2 is performed based on the presence/absence of electrical conduction between a pair ofelectrodes8bprovided in theinsertion portion2.

FIG. 29 illustrates a state before theinsertion portion2 of theheat monitoring instrument1 changes shape, andFIG. 30 illustrates a state after theinsertion portion2 changes shape.

As shown inFIG. 29, theheat monitoring instrument1 of the present embodiment includes aswitch portion8 that is arranged at thedistal end portion2aof theinsertion portion2. Theswitch portion8 includes the pair ofelectrodes8b, aplate spring8aand an insulatingmember8d. The pair ofelectrodes8bare arranged facing each other. The pair ofelectrodes8bare urged in a direction in which the pair ofelectrodes8bcome in contact with each other by theplate spring8a.

Aconductor wire8cextends from each of the pair ofelectrodes8b. Therespective conductor wires8care electrically connected to anunshown drive apparatus21 of thethermal therapy instrument20 through an electric cable. Thedrive apparatus21 stops operation of thethermal therapy instrument20 in a case where electrical conduction is confirmed between the pair ofelectrodes8bduring operation of thethermal therapy instrument20.

The insulatingmember8dis pinched between the pair ofelectrodes8b. The insulatingmember8dis made of a material that has electrical insulating properties and melts or softens when a predetermined temperature is exceeded. The material constituting the insulatingmember8dis, for example, beeswax, bone wax or paraffin.

In a case where the temperature of theinsertion portion2 is less than or equal to the predetermined temperature, as shown inFIG. 29, the pair ofelectrodes8bare separated by the insulatingmember8dthat is interposed therebetween, and electricity is not conducted between the pair ofelectrodes8.

If the temperature exceeds the predetermined temperature and the insulatingmember8dmelts or softens, as shown inFIG. 30, the pair ofelectrodes8bcome in contact with each other because of the urging force of theplate spring8a. That is, theswitch portion8 changes shape when the temperature exceeds the predetermined temperature, and establishes electrical conduction between the pair ofelectrodes8b.

The thermal therapy apparatus of the present embodiment configured as described above automatically stops thethermal therapy instrument20 in a case where theinsertion portion2 of theheat monitoring instrument1 changes shape during performance of the thermal therapy. Therefore, in a case where theinsertion portion2 of theheat monitoring instrument1 is heated such that the temperature thereof enters the predetermined temperature range that exceeds the predetermined temperature, thethermal therapy instrument20 can be reliably stopped.

Seventh Embodiment

A seventh embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the sixth embodiment are described, and components that are the same as in the sixth embodiment are denoted by the same reference numerals and a description of such components is omitted as appropriate.

FIG. 31 illustrates a state before theinsertion portion2 of theheat monitoring instrument1 changes shape, andFIG. 32 illustrates a state after theinsertion portion2 changes shape.

In theheat monitoring instrument1 of the present embodiment that is shown inFIG. 31, thedistal end portion2aof theinsertion portion2 is formed in a tube shape, and includes theswitch portion8 inside thedistal end portion2a. The tubulardistal end portion2ais formed of a material having electrical conductivity. Although the material constituting thedistal end portion2ais not particularly limited, for example, thedistal end portion2ais made of a metal that is biocompatible such as a stainless steel alloy or a Ni—Ti (nickel-titanium) alloy. In this connection, preferably theinner wall face2dof thedistal end portion2ais subjected to surface treatment that increases electrical conductivity, such as nickel plating. The internal space of thedistal end portion2athat is a tube shape is sealed by a sealingmember2c.

Theswitch portion8 includes aspring member8f, a holdingportion8g, anelectrode8eand an insulatingmember8d. Thespring member8fis an elongated rod-shaped or plate-shaped member that is formed of a material having electrical conductivity such as a metal. The proximal end portion of thespring member8fis fixed inside thedistal end portion2aby the holdingportion8g. The holdingportion8gis made of a material having electrical insulating properties.

Theelectrode8eis formed at the distal end portion of thespring member8f. Thespring member8fgenerates a force that urges theelectrode8fin a direction to contact theinner wall face2dof thedistal end portion2a.

The insulatingmember8dis pinched between theelectrode8eand theinner wall face2dof thedistal end portion2a. The insulatingmember8dis made of a material that has electrical insulating properties and melts or softens when a predetermined temperature is exceeded. The material constituting the insulatingmember8dis, for example, beeswax, bone wax or paraffin.

In a case where the temperature of theinsertion portion2 is less than or equal to the predetermined temperature, as shown inFIG. 31, theelectrode8eand theinner wall face2dof thedistal end portion2 are separated by the insulatingmember8dthat is interposed therebetween, and electricity is not conducted between theelectrode8eand theinner wall face2dof thedistal end portion2.

If the temperature exceeds the predetermined temperature and the insulatingmember8dmelts or softens, as shown inFIG. 32, theelectrode8ecomes in contact with theinner wall face2dof thedistal end portion2 because of an urging force of thespring member8f. That is, theswitch portion8 changes shape when the temperature exceeds the predetermined temperature, and establishes electrical conduction between theelectrode8eand theinner wall face2dof thedistal end portion2.

Theelectrode8eis electrically connected to theunshown drive apparatus21 of thethermal therapy instrument20 through thespring member8f, aconductor wire8hthat is connected to thespring member8f, and an electric cable. Theinner wall face2dof thedistal end portion2ais also electrically connected to theunshown drive apparatus21 of thethermal therapy instrument20 through an electric cable.

The thermal therapy apparatus of the present embodiment configured as described above automatically stops thethermal therapy instrument20 in a case where theinsertion portion2 of theheat monitoring instrument1 changes shape when thermal therapy is performed. Therefore, in a case where theinsertion portion2 of theheat monitoring instrument1 is heated such that the temperature thereof enters the predetermined temperature range that exceeds the predetermined temperature, thethermal therapy instrument20 can be reliably stopped.

Further, according to the present embodiment, in comparison to the sixth embodiment, since a situation does not arise in which the melted insulatingmember8dcomes in contact with the subject, it is not necessary to take into consideration the biocompatibility of the insulatingmember8d, and thus the degree of freedom in the selection of the material constituting the insulatingmember8dis increased.

Eighth Embodiment

An eighth embodiment of the present invention will be described hereunder. Hereunder, only differences with respect to the sixth embodiment are described, and components that are the same as in the sixth embodiment are denoted by the same reference numerals and a description of such components is omitted as appropriate.

FIG. 33 illustrates a state before theinsertion portion2 of theheat monitoring instrument1 changes shape, andFIG. 34 illustrates a state after theinsertion portion2 changes shape.

In theheat monitoring instrument1 of the present embodiment that is shown inFIG. 33, thedistal end portion2aof theinsertion portion2 is formed in a tube shape, and includes theswitch portion8 inside thedistal end portion2a. The tubulardistal end portion2ais formed of a material having electrical conductivity. Although the material constituting thedistal end portion2ais not particularly limited, for example, thedistal end portion2ais made of a metal that is biocompatible such as a stainless steel alloy or a Ni—Ti (nickel-titanium) alloy. In this connection, preferably theinner wall face2dof thedistal end portion2ais subjected to surface treatment that increases electrical conductivity, such as nickel plating. The internal space of thedistal end portion2athat is a tube shape is sealed by the sealingmember2c.

Theswitch portion8 includes a shape-changingportion8i, the holdingportion8g, theelectrode8eand adielectric fluid8j. The shape-changingportion8iis constituted by a shape-memory alloy that changes shape when heated to the predetermined temperature range that exceeds the predetermined temperature. A proximal end portion of the shape-changingportion8iis fixed to the inside of thedistal end portion2aby the holdingportion8g. The holdingportion8gis made of a material having electrical insulating properties.

Theelectrode8eis formed at a distal end portion of the shape-changingportion8i. Further, the internal space of thedistal end portion2ais filled with thedielectric fluid8jthat is a liquid that has electrical insulating properties.

When the shape-changingportion8ithat is made of a shape-memory alloy is less than or equal to the predetermined temperature, as shown inFIG. 33, the shape-changingportion8ibecomes an approximately rectilinear shape that extends in the longitudinal direction of thedistal end portion2 so that theelectrode8eand theinner wall face2dof thedistal end portion2 are separated. That is, in this case, electricity is not conducted between theelectrode8eand theinner wall face2dof thedistal end portion2.

On the other hand, when the shape-changingportion8iexceeds the predetermined temperature, as shown inFIG. 34, the shape-changingportion8ibecomes a bent shape so that theelectrode8eand theinner wall face2dof thedistal end portion2 come in contact. That is, in this case, electricity is conducted between theelectrode8eand theinner wall face2dof thedistal end portion2.

As described above, theswitch portion8 changes shape when the temperature exceeds the predetermined temperature, and establishes electrical conduction between theelectrode8eand theinner wall face2dof thedistal end portion2. Thedielectric fluid8jthat is filled inside thedistal end portion2 serves a role of transmitting the temperature of thedistal end portion2 to the shape-changingportion8iof theswitch portion8. Accordingly, if the temperature of thedistal end portion2 is less than or equal to the predetermined temperature, theelectrode8eof theswitch portion8 and theinner wall face2dof thedistal end portion2 enter an electrically insulated state, and if the temperature of thedistal end portion2 exceeds the predetermined temperature, theelectrode8eof theswitch portion8 and theinner wall face2dof thedistal end portion2 enter an electrically conducting state.

Theelectrode8eis electrically connected to theunshown drive apparatus21 of thethermal therapy instrument20 through the shape-changingportion8i, aconductor wire8hthat is connected to the shape-changingportion8i, and an electric cable. Theinner wall face2dof thedistal end portion2ais also electrically connected to theunshown drive apparatus21 of thethermal therapy instrument20 through an electric cable.

The thermal therapy apparatus of the present embodiment configured as described above automatically stops thethermal therapy instrument20 in a case where theinsertion portion2 of theheat monitoring instrument1 changes shape when thermal therapy is performed. Therefore, in a case where theinsertion portion2 of theheat monitoring instrument1 is heated such that the temperature thereof enters the predetermined temperature range that exceeds the predetermined temperature, thethermal therapy instrument20 can be reliably stopped.

The present invention is not limited to the above described embodiments, and may be suitably changed without departing from the spirit or concept of the invention readable from the appended claims and the entire specification, and a heat monitoring instrument and a thermal therapy apparatus with such changes are also included in the technical scope of the present invention.

[Supplementary Note 1]

A heat monitoring instrument including: an insertion portion to be inserted into tissue of a subject; and a switch portion that is provided in the insertion portion, and changes shape when heated from a state of a predetermined temperature or less to a predetermined temperature range that exceeds the predetermined temperature so that presence/absence of electrical conduction is switched.

[Supplementary Note 2]

The heat monitoring instrument according tosupplementary note 1, wherein the insertion portion is composed of a tubular member in which a distal end portion is sealed, and the switch portion is arranged inside the distal end portion of the insertion portion.

[Supplementary Note 3]

A thermal therapy apparatus that includes a heat monitoring instrument according tosupplementary note 1 or 2, a thermal therapy instrument that heats the tissue, and a drive apparatus that actuates the thermal therapy instrument; wherein in a case where switching of presence/absence of electrical conduction of the switch portion of the heat monitoring instrument is detected, the drive apparatus stops operation of the thermal therapy instrument.

Claims (6)

What is claimed is:

1. A heat monitoring instrument, comprising:

an insertion portion for inserting into tissue of a subject;

a locking portion provided on a distal end portion of the insertion portion, the locking portion being configured to engage with the tissue by being bent in a hook-like shape when the locking portion is at a predetermined temperature or less, and to eliminate being bent and release the engagement with the tissue when the locking portion is heated from the predetermined temperature or less to a predetermined temperature range that exceeds the predetermined temperature;

a linear member, a distal end portion of which is coupled to the insertion portion;

a holding portion configured to hold a proximal end portion of the linear member and to move in a distal end direction and a proximal end direction of the linear member;

an urging member configured to urge the holding portion in the proximal end direction to apply a tensile force to the linear member; and

a detection portion configured to detect movement of the linear member and the holding portion in the proximal end direction when the engagement of the locking portion with the tissue is released.

2. The heat monitoring instrument according toclaim 1, further comprising a cylindrical member, a distal end side of which has a cylindrical shape configured to be pierced into the tissue, and an inside of which the insertion portion can be inserted into.

3. A thermal therapy apparatus, comprising:

the heat monitoring instrument according toclaim 1,

a thermal therapy instrument that heats the tissue, and

a drive apparatus that actuates the thermal therapy instrument;

wherein the drive apparatus stops operation of the thermal therapy instrument in a case where the detection portion detects the movement of the holding portion in the proximal end direction during operation of the thermal therapy instrument.

4. The heat monitoring instrument according toclaim 1, further comprising a base fixed to a proximal end-side opening of a treatment instrument channel of an ultrasound endoscope.

5. The heat monitoring instrument according toclaim 4, further comprising a slider to which the holding portion is fixed, the slider being configured to move relatively with respect to the base by being urged by the urging member.

6. The heat monitoring instrument according toclaim 5, wherein the slider includes the holding portion configured to hold a proximal end portion of the linear member.

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